Cooling apparatus



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ATTORNEY Patented June 16, 1936 UNITED. STATES PATENT OFFICE COOLING APPARATUS Ernest F. Stalcup, Rutledge, Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application October 20, 1933, Serial No. 694,511

22 Claims.

novel means for controlling the operation of the ejector of a steam jet refrigerating system so that communication between the evaporating chamber and the ejector is permitted only during periods of normal operation of the ejector.

In refrigeration apparatus of the steam jet type, cooling of liquid is effected in a closed chamber by withdrawing vapor and non-condensable gases therefrom, which is effected by an ejector motivated by steam; or other condensable vapor. The vapor exhausted from the ejector is condensed in a condenser in which it is brought into heat exchanging relation with a cooling medium, usually water. As a low pressure I is maintained in the chamber by the ejector, the

liquid admitted thereto will vaporize at a low temperature; the latent heat of vaporization of l the portion of the liquid vaporized being abstracted from the body of liquid in the chamber sothat its temperature is substantially reduced.

It is desirable in the operation of equipment of this kind that the ejector be isolated from the evaporating chamber at times when its suction pressure is above the pressure to be maintained in the chamber. This condition is present during starting periods, and may also result when faulty operation of the ejector occurs. 7

The necessity of isolating the ejector is found particularly in apparatus embodying a plurality of ejectors, one or more of said ejectors being shut down for partial loads. In such case, reverse flow of vapor from the condenser to the evaporating chamber takes place through the ejector not in operation, unless communication therethrough is cut 01?.

, It is a particular object of my invention to provide control means operating to prevent reverse flow of vapor through the ejector by cutting off communication therethrough at the proper time. 45 In accordance with my invention, I provide a valve between the inlet of the ejector and the evaporating chamber, which valve is preferably operated by fluid under pressure. Means responsive to the pressure of vapor between said valve 50 and the inlet of the ejector is provided for controlling the operation of the valve, so that the valve is opened when the pressure in the ejector inlet has been reduced to a predetermined amount. Furthermore, the means referred to may be made responsive, differentially, to the A further object of my invention is to provide,

pressure in the ejector inlet and the pressure in the ejector outlet, whereby the valve is moved to a closed position when the difference in pressures in the inlet of the ejector and in the outlet thereof fall below a predetermined value. Al- '5' ternatively, the valve may be operated in response to the temperature of the vapor in the ejector inlet so that it is open when the temperature is. low and is closed when, for any reason, a reverse flow of steam from the condenser increases 10 the temperature in the inlet of the ejector.

The above and other objects are eifected by my invention, as will be apparent from the following description and claims taken in connection with the accompanying drawing forming a 1 5 part of this application, in which:

Fig. 1 is a diagrammatic view, showing a steam. jet refrigerating system arranged in accordance with my invention;

Fig. 2 is a sectional view of a detail included 2 in my invention.

Fig. 3 is a fragmentary diagrammatic view of a modification.

Referring now to Figs. 1 and 2 of the drawing, I show, in Fig. 1, an evaporating chamber l0 hav- 25 ing an inlet II for the admission of liquid to be cooled and an outlet 12 for liquid which has been cooled. The latter is connected to a conduit l3 provided with a pump M for conveying the cooled liquid to a point of use. The chamber in is in communication with the inlet connection 5 of an ejector 6, which includes a nozzle chamber 1 and a converging-diverging conduit portion 8. It is also connected through a valve I6 to the inlet connection I! of a steam ejector I8, the lat- 5 ter comprising a nozzle chamber I 9 and a converging-diverging conduit portion 20.

The exhaust ends of the ejectors 6 and I8 are connected to the vapor inlet 2! of a condenser 22 having connections 23 and 24 for the admission and discharge of a cooling medium, preferably water. The condenser 22 is provided with a connection 25 through which condensate and non-condensable gases may be withdrawn.

The ejectors 6 and 8 are motivated by steam or other suitable vapor which is condensable at the pressure at which it is exhausted from the ejector. The steam is supplied to the ejector [8 from any convenient source through a conduit 26 having a valve 21 connected therein. Motivating steam for the ejector 6 is controlled by the valve 9.

In accordance with the present invention, means are provided for isolating the ejector [8 from the evaporating chamber It), automatically, 5 5

when the pressure in the inlet connection I 1 rises above a predetermined value, such isolating means being shown in Figs. 1 and 2 as comprising a pressure responsive device 28, a pilot valve structure 29 operated thereby, and a motor device 3| operatively connected to the valve I6.

The motor device 3| includes a cylinder 32 having a piston 33 slidably mounted therein. Movement of the piston 33 is transmitted to the valve l6 by means of a piston rod 34. With the piston 33 in the position shown in Fig. 1, the valve l6 will be in its closed position and communication between the ejector inlet connection l1 and the evaporating chamber ID will be interrupted.

The pressure responsive device 28 and the pilot valve 29 are best shown in Fig. 2. The device 28 includes a casing 35 divided into chambers 36 and 31 by a diaphragm 38. The chamber 36 is connected by means of a conduit 39 to the inlet connection l1 and the chamber 31 is preferably connected to the inlet 2| of the condenser 22 by means of a conduit 4|. The diaphragm 38 is connected by means of a stem 42 to a valve 43, which is the movable element of the pilot valve structure 29. The latter includes also a cylinder 44 having heads 45 and 46. The structure 29 is secured in spaced relation to the pressure responsive device 28 by rods 41 and stufiing boxes 48 and 49 are preferably provided for the stem 42 where it passes through the casing 35 and cylinder head 45, respectively.

The valve 43 has spaced piston portions 5| and 52 formed thereon, which portions cooperate with ports 53 and 54 in the cylinder 44. The port 53 communicates with the portion of cylinder 32 on the upper side of the piston 33 by means of conduit 55 and the port 54 communicates with the portion of the cylinder 32 on the lower side of the piston 33 by means of conduit 56. A port 51 is formed in cylinder 44, and is in communication at all times with the space between the piston portions 5| and 52 and with a conduit 58 connected to a source of fluid pressure (not shown). A conduit 59 communicates with the ends of the cylinder 44 for conveying fluid therefrom to a point of discharge when the valve 43 is moved from one position to another.

During periods when the ejector I8 is shut down, or at any time when the pressure in the inlet-connection I1 is as great as the pressure in the connection 2|, the diaphragm 38 and valve 43 will be in their right hand positions as shown in Fig. 2. They are biased to this position by a spring 6 I, the bias of which may be adjusted conveniently by an adjusting screw 62 threaded in the casing 35 and supporting one end of the spring 6L- A stuffing box 63 may be provided for the screw 62 to prevent ingress of air into the chamber 36.

Assuming the apparatus to be shut down, the various elements will be in the positions shown in the drawing. As the valve 43 is in its extreme right hand position, pressure from the conduit- 58 is impressed on the underside of the piston 33 through the ports 51 and 54 and the conduit 56 so that the valve I6 is closed. Pressure on the upper side of the piston 33 will be relieved through the conduit 55 and the port 53, to the discharge conduit 59.

As the valve 9 is opened, motivating steam is supplied to the nozzles of the ejector 6 so that vapor and non-condensable gases in the chamber ID are entrained thereby and the mixture is discharged into the condenser 22. The pressure in the chamber I0 is reduced to a low value by the ejector 6 and cooling of the liquid entering through inlet I I, is efiected by evaporation. The cooled liquid is conveyed to a point of use by the pump I4.

As the demand for refrigeration increases the steam valve 21 is opened to admit motivating steam to the ejector l8. Vapor and non-condensable gases in the inlet connection H are entrained by the ejector I8 and are discharged into the condenser 22. The vapor discharged into the condenser 22 by both ejectors is condensed therein and the condensate and non-condensable gases may be withdrawn from the condenser 22 by any convenient means through the connection 25.

The pressure in the connection l1, conduit 39 and chamber 36 will drop due to the entrainment of vapor and gases by the ejector l8 and, when the pressure difference in the chambers 36 and 31 reaches a predetermined amount, as determined by the setting of the adjusting screw 62, the bias of the spring 6| will be overcome and the diaphragm 38, stem 42, and valve 43 will move to the left. The adjustment of the screw 62 will be such that movement of the valve 43 is effected when the pressure in chamber 36 is substantially equal to the pressure in chamber Ill. Pressure from supply conduit 58 will now be admitted to the cylinder 32 above the piston 33 through ports 51 and 53 and conduit 55. At the same time, pressure from below the piston 33 will be relieved through the conduit 56, port 54 to the discharge conduit 59. The valve l6 will, therefore, be opened to establish communication between the inlet connection ll of the ejector I8 and the evaporating chamber l0.

When the demand for refrigeration is reduced and the steam valve 21 is closed, the pressure in the condenser 22 and the inlet connection I1 equalize through the ejector I8. As the pressures in the chambers 36 and 31 become of substantially equal value, the bias of the spring 6| moves the Valve 43 to the position shown in the drawing. The pressure in the cylinder 32 above the piston 33 is relieved through the conduit 55 and port 53 to the discharge conduit 59 and pressure from the supply conduit 58 is admitted to the cylinder 32 beneath the piston 33 through ports 51 and 54 and conduit 56. The piston 33 moves upwardly to close valve I6 so that the ejector I8 is isolated from the evaporating chamber. The ejector l8 will now be in its inoperative or shut down" position.

The foregoing description relates to the normal operation of my improved refrigerating appara tus when started and stopped. It will be apparent, however, that operation of the valve IS in a closing direction will accompany any faulty operation of the ejector l8 which will cause a rise in pressure in the inlet connection l1. For example, in the event that the steam jet would become disrupted, for any reason, the tendency for steam to flow back into the evaporating chamber In would be prevented, as a rise in pressure in the inlet connection l1 and, consequently, in the chamber 36 would result. When the difference in pressures in chambers 36 and 41 drops to a. predetermined amount determined by the setting of the adjusting screw 62, the spring 6| would move the stem 42 and valve 43 to the position shown in the drawing and closing the valve l6 would result in the manner previously described.

It will be apparent that pressure sources other than the condenser 22 may be utilized for chamber 31, but I prefer to use the pressure of the condenser as it is maintained substantially constant at all times, so that a more accurate adjustment of the pressure responsive device 28 may be obtained.

It will be understood that the ejector 6, and any additional ejector, may also be equipped with a valve between its inlet and the evaporating chamber I0, and also the controlling means therefor, in the same manner as the ejector I8. In this event, either ejector would be isolated from the chamber I0 when inactive.

Reference will now be had to Fig. 3 in which I have shown means responsive to the temperature of the vapor in the ejector inlet for operating the valve I6. A thermostat I0 preferably includes a bulb II subjected to the temperature of the vapor in the inlet connection ll of the ejector I8" and an expansible bellows I2 connected to the bulb II by a tube 13. The bulb 'II, tube 13 and bellows I2 define a closed chamber in which a volatile fluid is enclosed so that with an increase of temperature in the inlet connection I1 the bellows 12 will expand and conversely with a decrease in temperature the bellows I2 will contract. Movement of the bellows 12 is transmitted to the valve 43 of the pilot valve structure 29' by means of a stem 42'.

When the ejector I8 is shut down, the bulb 'II is subjected to the temperature of the vapor at the discharge end thereof as the ejector forms an equalizing passage between its inlet connection I1 and its discharge end. As this temperature is relatively high, the bellows 12 will be expanded and the valve. 43' will be in its lowermost position as shown. As the construction and operation of the pilot valve structure 29' and the valve operating motor device 3| are the same as disclosed in Figs. 1 and 2, no detailed description of them, will be necessary and the operation'only will be described. In this position of the valve 43, pressure from the conduit .58 will be impressed on the under side of the piston 33' through conduit 56'. Pressure on the upper side of the piston 33 will be relieved through conduit valve structure 29', and the discharge conduit 59. The valve I6 is therefore closed.

As steam is admitted to the nozzles '14 of the ejector I8, vapor and non-condensable gases in the inlet connection II will be entrained by the steam jet so that the pressure and temperature of the vapor in the connection II will be substantially reduced. The bellows I2 contracts to move the valve 43' to its uppermost position.

' Pressure from the under side of the piston 33' is relieved through conduit 56 to the discharge conduit 59' and pressure from the supply conduit 58 is impressed on the upper side of the piston 33' through conduit 55'. The valve I6 opens to establish communication between the inlet connection I I and the chamber Ill.

As the supply of motivating fluid to the nozzles 14 is discontinued, the relatively high temperature vapor from the discharge end of the ejector I8 will back into the connection I1 and the thermostat 10 will then operate to close the valve I6 as described. It will be apparent that closure of the valve I6 will also accompany any breakdown in the jet during operation as the relatively warm vapor will flow back into the connection II where the thermostat bulb II is located.

From the foregoing, it will be seen that I have provided an improved steam jet refrigerating system in which communication between the inlet of an ejector and the evaporating chamber is established only when a condition in the ejector inlet is of a predetermined and desirable value, which value may be adjusted at will.

While I have shown my invention in two forms, it will be obvious tothose skilled in the art that it is not so limited, but is susceptible. of various other changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. In vapor jet refrigeration apparatus, the combination of an evaporating chamber, means for admitting liquid to said chamber, an ejector for withdrawing vapor from the evaporating chamber to effect partial evaporation and cooling of the liquid therein, and means respon 've to a condition effected by the ejecting actidn of the ejector for establishing communication between said ejector and evaporating chamber.

2. In vapor jet refrigeration apparatus, the combination of an evaporating chamber, means for admitting liquid to be partially evaporated and cooled to said chamber, an ejector for withdrawing vapor from the chamber, means forming a passage between said chamber and said ejector for conducting the withdrawn vapor to the ejector, and means for shutting off flow through the passage in response to a predetermined maximum temperature in the passage.

3. In vapor jet refrigeration apparatus, the combination of an evaporating chamber, means for admitting liquid to be partially evaporated and cooled to said chamber, an ejector for withdrawing vapor from the chamber, means forming a passage between said chamber and said ejector for conducting the withdrawn vapor to the ejector, and means for shutting off flow through the passage in response to a predetermined maximum absolute pressure in the passage.

4. In vapor jet refrigeration apparatus, the combination of an evaporating chamber, means for admitting liquid to be partially evaporated and cooled to said chamber, an ejector for withdrawing vapor from the chamber, means forming a passage between said chamber and said ejector for conducting the withdrawn vapor to the ejector, a valve in said passage, anmpans for operating said valve in accordance with pres sure conditions in the passage on the ejector side of the valve.

5. In vapor jet refrigeration apparatus, the combination of an evaporating chamber, means for admitting liquid to be partially evaporated and cooled to said chamber, an ejector having an inlet for withdrawing vapor from the chamber, means for conveying vapor discharged by the ejector, and means difierentially responsive to pressures in said inlet and said conveying means for controlling the flow of vapor from the chamber to the ejector.

6. In vapor jet refrigeration apparatus, the combination of an evaporating chamber, means for admitting liquid to be partially evaporated and cooled to said chamber, an ejector for withdrawing vapor from the chamber, means forming a passage between said chamber and said ejector for conducting the withdrawn vapor to the ejector, means for condensing the vapor discharged by the ejector, and means for controlling the flow of vapor from the chamber to the passage in accordance with conditions in the passage and the condensing means.

7. In vapor jet refrigeration apparatus, the combination of an evaporating chamber, means for admitting liquid to be partially evaporated and cooled to said chamber, an ejector for withdrawing vapor from the chamber, means forming a passage between said chamber and said ejector for conducting the withdrawn vapor to the ejector, means for condensing the vapor discharged by the ejector, and means for controlling the flow of vapor from the chamber to the passage in accordance with pressure differentials between the passage and the condensing means.

8. In vapor jet refrigeration apparatus, the combination of an evaporating chamber, means for admitting liquid to be partially evaporated and cooled to said chamber, an ejector for withdrawing vapor from the chamber, means forming a passage between said chamber and said ejector, for conducting the withdrawn vapor to the ejector, means for condensing the vapor discharged by the ejector, and means for controlling the flow of vapor from the chamber to the passage in accordance with pressure difierentials between the passage and the condensing means, and means for adjusting said pressure differentials.

9. In vapor jet refrigeration apparatus, the combination of an evaporating chamber, means for admitting liquid to be partially evaporated and cooled to said chamber, an ejector having an inlet for withdrawing vapor from the chamber, a valve for controlling the flow of vapor from the chamber to the inlet of said ejector, a condenser for. condensing vapor discharged by the ejector, and a device differentially responsive to pressures in the condenser and said inlet for operating said valve.

10. In vapor jet refrigeration apparatus, the combination of an evaporating chamber, means for admitting liquid to be partially evaporated and cooled to said chamber, an ejector having an inlet for withdrawing vapor from the chamber, a valve for controlling the flow of vapor from the chamber to said ejector, a condenser for condensing vapor discharged by the ejector, and a device differentially responsive to pressures in the condenser and said inlet for operating said valve, and means for adjusting the pressure differential at which said device operates.

11. In vapor jet refrigeration apparatus, the combination of an evaporating chamber, means for admitting liquid to be partially evaporated and cooled to said chamber, an ejector having an inlet for withdrawing vapor from said chamber, a valve for controlling the flow of vapor from the chamber to the inlet of said ejector, a condenser for condensing vapor discharged by the ejector, and a device, differentially responsive to the discharge pressure of saidejector and the pressure in said inlet, for controlling the operation of the valve.

12. In vapor jet refrigeration apparatus, the combination of an evaporating chamber, means for admitting liquid to be partially evaporated and cooled to said chamber, an ejector, a conduit between said ejector and said chamber for conveying vapor and other non-condensable gases from the chamber to the ejector, means for conveying vapor and non-condensable gases discharged by the ejector, a valve in said conduit for controlling the passage of gases and vapor from the chamber to the ejector, and a device difierentially responsive to pressures in said conduit and said conveying means for controlling the operation of the valve; said device including hydraulic means for opening and closing the valve, 2. control valve for controlling the flow of fluid to said hydraulic means, a casing, a diaphragm disposed within the casing for actuating said control valve, means providing communication between said casing on one side of the diaphragm with said conduit, and second means providing communication between said casing on the other side of the diaphragm with said conveying means.

13. In refrigeration apparatus, the combination of an evaporating chamber, means for admitting liquid to said chamber for partial evaporation and cooling, a fluid translating device for withdrawing vapor from the chamber, a conduit for conveying said withdrawn vapor, means for conveying vapor discharged by the fluid translating device, a valve disposed between said conduit and the chamber, and means differentially responsive to the pressure in said conduit and the pressure in said conveying means for operating said valve.

14. In refrigeration apparatus, the combination of an evaporating chamber, means for admitting liquid to said chamber for partial evaporationv and cooling, a fluid translating device for with-- drawing vapor from the chamber, a conduit'for conveying said withdrawn vapor, a valve between said conduit and said chamber, a condenser, means for conveying vapor discharged by the fluid translating device to the condenser, and means differentially responsive to conditions in said conduit and said conveying means for operating said valve.

15. In vapor jet refrigeration apparatus, the combination of an evaporating chamber, means for admitting liquid to be partially evaporated and cooled to said chamber, an ejector for withdrawing vapor from the chamber, means forming a passage between said chamber and said ejector for conducting the withdrawn vapor to the ejector, and means for regulating the flow of vapor from the chamber to the passage in accordance with the temperature in the passage.

16. In vapor jet refrigeration apparatus, the combination of an evaporating chamber, means for admitting liquid to be partially evaporated and cooled to said chamber, an ejector having nozzles for withdrawing vapor from the chamber, means forming a passage between said chamber and said ejector for conducting the withdrawn vapor to the ejector, a valve in said passage and means responsive to the temperature of the vapor adjacent the nozzles for operating said valve.

17. In refrigeration apparatus, the combination of an evaporating chamber, means for admitting liquid for partial evaporation and cooling to said chamber, a fluid translating device for withdrawing vapor and non-condensable gases from the chamber, means forming a passage from the chamber to the translating device, m'eans for controlling the flow of gases and vapor from the chamber to the passage and means responsive to the temperature of the vapor in said passage for operating said controlling means.

18. In vapor jet refrigerating apparatus, the

combination of an evaporating chamber, an ejector for withdrawing vapor from said chamber to effect cooling by evaporation of liquid therein, a valve controlling communication between the evaporating chamber and the ejector, and means responsive to a condition effected by the ejecting action of the ejector for opening said valve and responsive to a condition occurring upon absence or failure of ejecting action of the ejector for closing said valve.

19. In vapor jet refrigerating apparatus, the combination of an evaporating chamber, an ejector having nozzles for withdrawing vapor from said chamber to efiect cooling by evaporation of liquid therein, means for supplying motive fluid to said nozzles, a valve controlling communication between the evaporating chamber and the ejector, and means responsive to a condition of the ejector indicating that motive fluid from the ejector nozzles is flowing to the evaporating chamber for closing said valve.

20. In vapor jet refrigerating apparatus, the combination of an evaporating chamber, an ejector connected to said chamber for withdrawing vapor therefrom to efiect cooling by evaporation of liquid, and means, responsive to a predetermined maximum temperature in the space from which said ejector withdraws vapor indicating flow of motive fluid into said space, for preventing further heating of said evaporating chamber by said motive fluid.

21. In vapor jet reifrigerating apparatus, the combination of an evaporating chamber, an ejector connected to said chamber for withdrawing vapor therefrom to effect cooling by evaporation of liquid, a valve for controlling communication between said chamber and said ejector, and means, responsive to a predetermined maximum temperature in the space from which said ejector withdraws vapor indicating flow of motive fluid into said space, for closing said valve to prevent further heating of said evaporating chamber by said motive fluid.

22. In vapor jet refrigerating apparatus, the combination of an evaporating chamber, an ejector connected to said chamber for withdrawing vapor therefrom to eifect cooling by evaporation of liquid, and means, responsive to flow of motive fluid into the space from which the ejector normally withdraws vapor, for preventing further heating in said evaporating chamber by said motive fluid.

ERNEST F. STALCUP. 

